This book is a printed edition of the Special Issue Selected Papers from the 15th Estuarine and Coastal Modeling Conference that was published in JMSE

In the next century, sea levels are predicted to rise at unprecedented rates, causing flooding around the world, from the islands of Malaysia and the canals of Venice to the coasts of Florida and California. These rising water levels pose serious challenges to all aspects of coastal existence—chiefly economic, residential, and environmental—as well as to the cartographic definition and mapping of coasts. It is this facet of coastal life that Mark Monmonier tackles in Coast Lines. Setting sail on a journey across shifting landscapes, cartographic technology, and climate change, Monmonier reveals that coastlines are as much a set of ideas, assumptions, and societal beliefs as they are solid black lines on maps. Whether for sailing charts or property maps, Monmonier shows, coastlines challenge mapmakers to capture on paper a highly irregular land-water boundary perturbed by tides and storms and complicated by rocks, wrecks, and shoals. Coast Lines is peppered with captivating anecdotes about the frustrating effort to expunge fictitious islands from nautical charts, the tricky measurement of a coastline’s length, and the contentious notions of beachfront property and public access. Combing maritime history and the history of technology, Coast Lines charts the historical progression from offshore sketches to satellite images and explores the societal impact of coastal cartography on everything from global warming to homeland security. Returning to the form of his celebrated Air Apparent, Monmonier ably renders the topic of coastal cartography accessible to both general readers and historians of science, technology, and maritime studies. In the post-Katrina era, when the map of entire regions can be redrawn by a single natural event, the issues he raises are more important than ever.

"NOAA has typically updated tidal datum elevations for the nation to new National Tidal Datum Epoch (NTDE) time periods every 20-25 years. Updates at this frequency are necessary due to long-term global sea level change. In 1998, NOS recognized the need for a modified procedure that utilized more frequent time period updates, for determination of tidal datums for regions with anomalously high rates of local relative sea level change. These localized effects in relative sea level trends are typically due to different forces other than those responsible for global trends which can vary significantly from global trends in both time scales and magnitude. This modified procedure is necessary at selected stations to ensure that the tidal datums accurately represent the existing stand of sea level relative to land on which these datums are held fixed. Bench mark monuments are typically used as reference points for numerous applications requiring tidal datum references. The modified procedure is limited only to those stations with documented anomalous relative sea level trends due to high rates of vertical land motion. Anomalous relative sea level trends are seen along the central Louisiana, the southern Cook Inlet, and the southeastern Alaska coasts. For example, the magnitude of the sea level trends in these areas are +9.24 mm/yr at Grand Isle, LA; -9.45 mm/yr at Seldovia, AK; and -12.92 mm/yr at Juneau, AK. Following the first implementation of the modified procedure in 1998, using the time series for tidal datum computation of 1990-1994, sea level analyses in these anomalous regions are now conducted approximately every five (5) years to identify stations that require datum updates using the modified procedure...The purpose of this technical report is to document the Modified Procedure that has been used by CO-OPS to compute accepted tidal datums for selected regions having anomalously high rates of local relative sea level change. Additionally, the report provides an update on near-term plans for continuing to implement the procedure"--Executive Summary.